Infusion monitoring device



06f. v1 1963 M. R. scHoENFELD l INFUSION MONITORING DEVICE Filed Feb. 25. 1960 FIG. 3

INVENTOR MYRON R. SCHOENFELD FIG.2

Vfull-blown pulmonary edema may ensue.

3,105,490 INFUSIN MNITORING DEVICE Myron R. Schoenfeld, 277 Bronx River Road, Yonkers, NY. Filed Feb. 25, 1960, Ser. No. 10,947 5 Claims. (Cl. 12S-214) The present invention relates to the art of intravenous infusion, and particularly to a new and improved apparatus for monitoring and controlling the amount of an intravenous infusion.

One of the greatest triumphs of modern medicine has been the mastery of intravenous feeding. Today it is the exceptional hospital patient who, during his stay on a medical or surgical service, does not receive at least one type of infusion. Blood, plasma, saline, glucose, fructose, and other agents are all regularly given intravenously by slow drip in volumes of 50G-3000 cc. or more when indicated, and innumerable lives have been saved by these agents. Despite the general safety and ease of administration of these uids, there are problems associated with their use. Among these problems is the controlling of the amount of the infusion over a given time interval and avoiding a complete emptying of the infusion container.

While an unnoticed slowing of the infusion rate has sometimes caused great ditliculty, an unnoticed acceleration of the rate is a more frequently encountered problem. Excessive rate of infusion may be due to a ow rate actually faster than intended by the physician, or a rate which proceeds to emptying of the infusion bottle without the knowledge of the medical staff.

During cardiac or renal failure, there is retention of abnormal amounts of iluid in the body and an expanded blood volume. The latter places an extra load `on the heart, thus creating a vicious cycle. If one loads the circulatory system ltoo rapidly with intravenous fluids (particularly saline), further cardiac decompensation and This danger is a frequently encountered problem in the older age `groups in patients with compromised cardiac reserves due to iarteriosclerotic and/or hypertensive heart disease.

Nevertheless, in hospital practice one must often administer parenteral uids to these patients, frequently on a around-the-clock basis. The rate of infusion set 'by the physician may be inadvertently accelerated by the patient moving his arm and thereby changing the position of the needle tip in relation to the vein wall. Should this occur at night when medical supervision is at a minimum, rapid infusion may continue for a -long enough period of time to endanger life.

fusion pressure is `generally maintained at this high level prophylactically because of the possibility of meeting high right atrial yor right ventricular pressures such as may be encountered-in left to right shunts. Particularly -in diicult cases, the attending medical personnel may be so busy with the technicalities of the procedure that,

occasionally, the infusion bottle runs dry, and air, under `a head of pressure of 150 to 200 mm. Hg ror more, is

injected intravenously or intra-arterially. The empty infusion bottle may go undetected until the patient develops neurologic signs, abdominal pain, other evidence of air embolism, or 'sudden death. Particular care is essential in right-sided procedures, not only because they are more United States Patent O lCe frequently performed, but also because the air pressure in the infusion bottle is almost unopposed by the very low central venous pressure.

In some patients-children, patients in shock, etc.- veins accessible for intravenous infusion are at a premium. Should the infusion bottle inadvertently run dry, backflow of blood into the needle usually occurs, with clotting and hence occlusion of the needle. The needle must then be removed and another vein sought. If one cannot be found, recourse must be taken to a cut-down, which-is a time-consuming, somewhat mutilating procedure.

Whole blood and some of its derivatives are quite viscous, and flow through an ordinary sized needle (#20-22) very sl-owly. To expedite the speed of transfusion (eg. in cases of hemorrhagic shock), air is sometimes pumped into the bottle. The danger of air embolism inherent in such cases is more than a potential problem.

In each of the aforementioned conditions, the common denominator is too rapid an emptying of the infusion bottle without the awareness of supervisory medical personnel.

An important object of this invention is to provide an infusion monitoring device capable of overcoming the above and other difficulties.

Another object of this invention is to provide such a monitoring device of simple and reliable construction.

Another object of the invention is to provide such an infusion monitoring ldevice in which a predetermined desired amount of intravenous infusion will not be exceedetd.

Still another object of the invention is to provide such an infusion monitoring device -in which alarm signals become effective to warn physicians and attendants of imminent danger.

Another object or" the invention is to provide such an infusion monitoring device capable of preventing infusion in quantities greater than those intended by the physician.

Still another object of this invention is to provide such an infusi-on monitoring device capable of preventing the complete emptying of the bottle of uid being infused 'Without supervisory personnel being warned.

Another object of the invention is to pro-vide such an inusion monitoring device which will cut oli the ow of infusion liquid when the contents of the bottle have reached a predetermined level.

In one aspect of the invention, an inverted bottle of infusion liquid, to which may be connected the usual flexible Itube and injection needle, may be supported from a pivoted lever. Adjustable means may fact upon the pivoted lever, tending to counterbalance the Weight of the inusion bottle. The construction and arrangement of the parts may be suchv that upon a predetermined decrease in the weight of the bottle of infusion liquid, due to intravenous infusion, the lever is caused to move about its pivot.

tIn another aspect of the invention, an electrical circuit may be energized by the pivoting of the lever to render yeffective certain signals to alert the supervisory personnel to :the condition of the infusion device.

In still another aspect of the invention, a positive acting device may be provided for interrupting the ow of the infusion liquid through the -llexible tube leading from the infusion bottle to the hypodermic needle when the alerting signals ane rendered effective.

In still another aspect of the invention, a light-sensitive means may be employed to energize the alerting signals and cut-olf means. The light-sensitive means and a source of light may be mounted for simultaneous elevational adjustment, so that predetermined amounts of inusion liquid may be injected.

Theabove, other objects and `advantages of the iming which is merely exemplary.

In the drawing: Y Y FIG. l yis an elevational View yofV apparatus to which the principles of 'the invention have been applied;

device will become apparent d with the magnet 34 :and lbecome illuminated. One of these lights may be located yat the device to warn the attending physician, while the other-inlay be C-ated at FIG. 2 is an elevational View of apparatus to which a l modified yform of the invention has been applied; and

FIG. 3 is a schematic wiring diagram of an electrical circuit for the apparatus shown in FIGS. l and 2.

Referring to the drawing, and particularly to FIG. l,

the principles of the invention are shown as applied to a housing 10 in which may be mounted a lever 1l for oscillatable movement about a pivot point 12. The lever 11 may be supported by a spring 13 that'lhas its one end Y fixed to the lever and its other end xed to a non-rotatable member 14 that is journaled on, and axially movable with, a rotatable screw-15. The member I4 is provided with'a pointer 16 rthat extends outwardly through a slot 16 within the lone sidewall @of housing l@ and cooperates with a scale 17. The screw'l may threadingly extend through a boss fixed to Ithe top wall of housing 10 and may have a crank 18 connected to the end extending outside of the housing 10. Accondingly, rotation of crank 18 will raise or lower the member 14, imparting to lever Il a greater or lesser resilient Vforce tending to raise Y it. A link I9 may be lxed to the lever 1l, and it may extend downwardly through the bottom of :housing 10 and `may include a hook 2d. A cage 21, adapted to support an inverted bottle 220i? infusion liquid 23, may include a handle 24 radapted to be :supported from the hook 20. VFrom the foregoing it is evident that the bottle 22 is supported by the spring 13, and the actual limits of 'movement of the lever-lll are determined by a stop 25.

Furthermore, the spring 13 may have suc-h a spring constant that when a1000 cc. bottle 22 is lled with infusion liquid and supported as :shown in LFIG. l, lever-11 will be in a horizontal position. The scale 17 may be calibrated, for example, in increments of 100 cc. Thus, if the pointer 16 is in the position shown, the lever 1l willremain against the lower surface of stop 25 until Vthe liquid within the bottle 22 has been reduced to 500 .tubular connector 3i) through which conductors may pass as will be described later. The cut-off device may include a rigidly mounted anvil 31 and a pivotally mounted lever 32 of magnetic material. A shoe 33 may be tixed to the lever 32 `for cooperation with lthe anvil 3l, and the exible tube v23 may pass between the shoe 33 and the anvil 3l. An electromagnetic device 34 may be xed within housing 29 in position to draw the arm 32 toward itwhen the device 34 is energized, thus clamping the tube 2S between shoe 33 and'anvil 3l to thereby cut oil-the ow of infusion liquid through lthe tube 28.

Referring to FIGS.' =l and 3, the lever Il may be pro'- Y vided with an arm 35 to which is attached a position sen- Y sitive switch 3d which in the'ernbodiment disclosed is shown as Va mercury switch. l rIhe mercury switch may be in open circuit condition when the lever-'11 is horizontal, but'in closed circuit condition when lever 11 is in the position shown in iFIG. 1.

A transformer 37 mayY be Vprovided if it is desired to operate the device on low voltage to prevent ruhe patient or attendants lbeing'inadvertently shocked. Closing of the switch 36 by the raising `of lever 11 due to the consump 'tion' of the infusion liquid causes the magnet 34 to be energized, thus ystopping the flow of infusion liquid through the tube28. Warning lights 38 and 39 may be in parallel the nurses station outside Kof the room. A bedside buzzer 40 may be provided for also warning the attending physician during ydaytime intravenous iniusion. Switches 41, 42, 43 and 43 maybe provided, respectively, in the circuits for lamps 38, 39, the ibuzzer 4t) and the electromagnet 34, so that flexibilityof operation is insured.

Referring fno FIG. 2, the principles orf the invention are shown as applied tota modified form or apparatusincluding a housing 44 that is connected to an Iarm 45 adapted iadjustably to be locked to a supporting standard 46 by a wing nut 47. The housing 44 maybe open at Vits bottom and may be provided with an elongated cylindrical surface 48 for guiding an inverted bottle of infusion liquid. A

light source 49 may be located within one of the side walls of housing 44 near the open end thereof. A photoelectric cell Sil may be located in a side wall of housing 44 diametrically opposite the light source 49. A filter 51 may be mounted between said photo-electric cell 50 and the bottle 22.

A counterbored plate 52Vmfay be xed rto anarm 53 that is adjustably secured to the standard 46 yby la wing nut 54. The lower end of the inverted bottle 22 is adapted to register with the counterbore lof plate 52 and to be guided by the cylindrical surface 48.

From the tforegoing it is evident that with either housing-44 or plate 52 xed, #adjustmentV of the other vsn'll vary the elevational position of the light source 49 and -photo-electric icell 50 relative to thel bottle 22, thereby providing a means for monitoring the ow of infusion liquid through theV exible hose 28. A stationary scale 55 may be provided yfor indicating the location of the light source 49 and photo-electric cell '50 relative to the icontents of the bottle 22. The photo-electric cell 50 may be connected in a known manner to lan amplier 56, which in turn may be connected to a sensitive relay 57 that is adapted to operate the switch 36 of FIG. 3.

, The infusion liquid may be mixed with a harmless coloring agent such as Biorrocca-C which is a mix-ture `of vitamins B andy C. It is'often added to infusion solutions to provide parenteral vitamin therapy and is quite safe. Adding 2 to 4 orf Borrocca-C to a liter of clear infusion liquid -(e.g., 5% glucose in water) produces la strong yellowish color. Light :transmitted through this solution Vemerges mainly as yellow. The complement of yellow is indigo blue, and an indigo bluelter glass 51 will transmit all colors except yellow. Accordingly, the cell 50 will notrespond to yellow light. As long as the light from the source 49 passes through the yellow infusion liquid, the cell 5d is not activated. When, however, the meniscus falls below the level of the light source and photo-electric cell, the, emitted light passes through the air-filled bottle. 'Dhe filter fails to pass the yellow wavelengths, but the remaining light fthat is transmitted isV sufficient ro activate the photo-electric cell 50. The Weak signal generated by the cell 50 is amplied in the amplier 56, land the amplitied signal activates the sensitive relay 57 which in turn aetuates switch 36 of the warning and cut-01T circuit of K FIG. 3. p

From the foregoing.` it is evident that an infusion monitering device has been provided that is capable of monitoring the dow/of intravenous yor intra-arterial infusions 'and which is capable of avoidi-ng,or even preventing a greater amount :being infused than intended by the physician. Likewise, the monitoring device is capable of preventing the bottle from becoming empty without the awareness of the supervisory staff. In special embodiments, the tlow of the infusion liquid is automatically cut orf before the bottlebecomes empty, thereby avoiding the hazards two embodiments of the invention, it will be evident that changes may be made in such details and certain features may be used without others Without departing tfrom the principles of the invention.

Wlhat is claimed is:

1. In an infusion monitoring device for controlling intravenous infusion, the combination comprising a container 'adapted to contain infusion liquid; means resiliently supporting said lcontainer in an inverted position; means for adjusting said resilient means; positive cut-off means lfor stopping the liquid flow from the container; and means responsive to a preset condition of said adjusting means -for actuating said cutoff means when the liquid Within said container is at a predetermined level.

2. In an `infusion monitoring device for controlling intnavenofus infusion, the combination comprising a container adapted to contain infusion liquid; means resiliently supporting said container in lan inverted position; means ttor adjusting said resilient means; signal means; positive cutdol means for stopping the l-iquid ow from the container; land means responsive to a preset conditi-on of said adjusting means for simultaneously actuating said signal means and said cut-oft means when the liquid Within said container is at a predetermined level.

3. In an infusion monitoring device for controlling intravenous infusion, the combination comprising a pivotally mounted lever; a container of infusion liquid suspended from said lever in an inverted position; a spring having its one end connected to said lever and its other end connected to an element adjustably movable 'along the line ci force of said spring to move said lever in response to the presence tof a variable but predetermined desired quantity or liquid in said container; circuit making and breaking means responsive to the movement of said lever; and signal means and a positive cot-oit device for cutting off the flow of liquid from said container adapted to be actuated by Athe making ior said circuit means.

4. In an infusion monitoring device for controlling intravenous infusion, the combination comprising a pivotally mounted lever; la container of infusion liquid suspended from said lever in an inverted position; a spring having its one end connected to said lever and its other tend connected to lan element tadjustably movable along the line of force of said spring; circuit making and breaknig means responsive to the movement 4of said lever; and electromagnetic positive cut-oit means adapted to be actuated by fthe making of said circuit means to stop the W of liquid from said container.

5. In an infusion monitoring vdevice for controlling intnavenous infusion, the combination comprising a pivotally mounted lever; a container of infusion liquid suspended from said lever in an inverted position; a spring having its one end connected to said lever fand its other end oonnected to an element adjustably movable along the line of force of said spring; circuit making and breaking means responsive to the movement off said lever; signal means; electromagnetic positive cut-otf means; and means responsive to the making `of said circuit means for simultaneously actuating said signal means and said cut-off means to stop the iiow ci liquid from said container.

References Cited in the file of this patent UNITED STATES PATENTS 1,455,795 Logan May 22, 1923 1,604,492 Smith Oct. 26, 1926 2,490,627 Hoberg Dec. 6, 1949 2,705,493 Malmros Apr. 5, 1955 2,706,755 Krasno Apr. 19, 1955 2,784,932 Poitras Mar. 12, 1957 2,835,252 Mauohel May 20, 1958 2,927,582 Berkman et `al Mar. 8, 1960 3,014,481 Rumble et 'al Dec. 26, 1961 

1. IN AN INFUSION MONITORING DEVICE FOR CONTROLLING INTRAVENOUS INFUSION, THE COMBINATION COMPRISING A CONTAINER ADAPTED TO CONTAIN INFUSION LIQUID; MEANS RESILIENTLY SUPPORTING SAID CONTAINER IN AN INVERTED POSITION; MEANS FOR ADJUSTING SAID RESILIENT MEANS; POSITIVE CUT-OFF MEANS FOR STOPPING THE LIQUID FLOW FROM THE CONTAINER AND MEANS RESPONSIVE TO A PRESET CONDITION OF SAID ADJUSTING MEANS FOR ACTUATING SAID CUT-OFF MEANS WHEN THE LIQUID WITHIN SAID CONTAINER IS AT A PREDETERMINED LEVEL. 